Population-based Familial Aggregation of Eosinophilic Esophagitis Suggests a Genetic Contribution

Publication date: Available online 10 February 2017
Source:Journal of Allergy and Clinical Immunology
Author(s): Kristina Allen-Brady, Rafael Firszt, John C. Fang, Jathine Wong, Ken R. Smith, Kathryn A. Peterson
BackgroundPrior familial clustering studies have observed an increased risk of eosinophilic esophagitis (EoE) mostly among first-degree relatives suggesting a genetic contribution to EoE, and twin studies have suggested a powerful contribution from environmental factors.ObjectiveClarify the contribution of genetic factors to EoE through estimation of familial aggregation and risk of EoE in extended relatives.MethodsThe Utah Population Database, a population-based genealogy resource linked to electronic medical records for healthcare systems across the state of Utah, was used to identify EoE cases and age, sex and birthplace-matched controls at a 5:1 ratio. Logistic regression was used to determine the odds of EoE among relatives of EoE probands compared to the odds of EoE among relatives of controls.ResultsThere were 4,423 EoE cases and 24,322 controls. The population attributable risk of EoE was 31% (95% CI 28-34%), suggesting a relatively strong genetic contribution. Risks of EoE were significantly increased among first-degree relatives (OR=7.19; 95% CI 5.65–9.14), particularly first-degree relatives of EoE cases diagnosed <18 years of age (OR=16.3; 95% CI 9.4-28.3); second-degree relatives (OR=1.99; 95% CI 1.49-2.65); and first cousins (OR=1.35; 95% CI 1.03-1.77), providing evidence of a genetic contribution. However, spouses of EoE probands were observed to be at increased risk of EoE (OR=2.86; 95% CI 1.31-6.25), suggesting either positive assortative mating or a shared environmental contribution to EoE.ConclusionThis study supports a significant genetic contribution to EoE as evidenced by increased risk of EoE in distant relatives.

Teaser

This study provides evidence of a genetic contribution to eosinophilic esophagitis as indicated by excess familial clustering of the disease in both close and distant relatives.


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